This proposal introduces a new concept of high temperature protective coating.
In hot harsh environments some components require surface protection: typical applications are thermal protection systems (TPS), hot structures for hypersonic vehicles and hot sections of gas turbines.
In oxidizing atmospheres, above 1300°C, ceramics or ceramic matrix composites are selected for their oxidation resistance and mechanical strength at high temperature. However their durability is adversely affected by water vapour from combustion or atmosphere.
In the proposed thermal and environmental barrier coating (TEBC), deposited by plasma spray, the multilayer modular architecture assigns to each layer a distinctive protective function. The external layer is an innovative Ultra High Temperature Ceramics (UHTCs) coating with an outstanding oxidation resistance at extreme temperatures; this layer acts as an environmental barrier coating (EBC), protecting the inner layers. Two or more ceramic-metallic layers complete the system architecture: the ceramic layers provide the thermal insulation and the metallic ones promote the compliance inside the TEBC and the adhesion to the substrate.
Current EBC limits are the maximum service temperature and the low thermal shock and thermal cycling resistance: the proposed system is designed to improve toughness, adhesion and cohesion using multiple metallic bond coats, providing an overall thermal conductivity tailorable by a proper stacking design of ceramic layers.
The proposal involves the preliminary study, characterization, design of the new system. A Finite Element Model will be created to optimize coating architecture, simulating the service conditions. A significant experimental effort will be devoted to evaluate physical and mechanical properties of studied materials as a function of temperature.
Finally an optimized coating will be the produced with a properly designed microstructure and its behavior will be evaluated in relevant environment
